Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
f1adc05e | 2 | * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
1da177e4 LT |
3 | * Licensed under the GPL |
4 | * | |
5 | * Ported the filesystem routines to 2.5. | |
6 | * 2003-02-10 Petr Baudis <pasky@ucw.cz> | |
7 | */ | |
8 | ||
1da177e4 | 9 | #include <linux/fs.h> |
1da177e4 | 10 | #include <linux/module.h> |
84b3db04 | 11 | #include <linux/mm.h> |
1da177e4 | 12 | #include <linux/pagemap.h> |
1da177e4 | 13 | #include <linux/statfs.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
dd2cc4df | 15 | #include <linux/seq_file.h> |
6966a977 | 16 | #include <linux/mount.h> |
d0352d3e | 17 | #include <linux/namei.h> |
1da177e4 | 18 | #include "hostfs.h" |
1da177e4 | 19 | #include "init.h" |
84b3db04 | 20 | #include "kern.h" |
1da177e4 LT |
21 | |
22 | struct hostfs_inode_info { | |
1da177e4 | 23 | int fd; |
aeb5d727 | 24 | fmode_t mode; |
1da177e4 LT |
25 | struct inode vfs_inode; |
26 | }; | |
27 | ||
28 | static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode) | |
29 | { | |
f1adc05e | 30 | return list_entry(inode, struct hostfs_inode_info, vfs_inode); |
1da177e4 LT |
31 | } |
32 | ||
680b0da9 | 33 | #define FILE_HOSTFS_I(file) HOSTFS_I((file)->f_path.dentry->d_inode) |
1da177e4 | 34 | |
e16404ed | 35 | static int hostfs_d_delete(struct dentry *dentry) |
1da177e4 | 36 | { |
f1adc05e | 37 | return 1; |
1da177e4 LT |
38 | } |
39 | ||
e16404ed | 40 | static const struct dentry_operations hostfs_dentry_ops = { |
1da177e4 LT |
41 | .d_delete = hostfs_d_delete, |
42 | }; | |
43 | ||
44 | /* Changed in hostfs_args before the kernel starts running */ | |
a6eb0be6 | 45 | static char *root_ino = ""; |
1da177e4 LT |
46 | static int append = 0; |
47 | ||
48 | #define HOSTFS_SUPER_MAGIC 0x00c0ffee | |
49 | ||
92e1d5be AV |
50 | static const struct inode_operations hostfs_iops; |
51 | static const struct inode_operations hostfs_dir_iops; | |
d0352d3e | 52 | static const struct inode_operations hostfs_link_iops; |
1da177e4 LT |
53 | |
54 | #ifndef MODULE | |
55 | static int __init hostfs_args(char *options, int *add) | |
56 | { | |
57 | char *ptr; | |
58 | ||
59 | ptr = strchr(options, ','); | |
84b3db04 | 60 | if (ptr != NULL) |
1da177e4 | 61 | *ptr++ = '\0'; |
84b3db04 | 62 | if (*options != '\0') |
1da177e4 LT |
63 | root_ino = options; |
64 | ||
65 | options = ptr; | |
84b3db04 | 66 | while (options) { |
1da177e4 | 67 | ptr = strchr(options, ','); |
84b3db04 | 68 | if (ptr != NULL) |
1da177e4 | 69 | *ptr++ = '\0'; |
84b3db04 JD |
70 | if (*options != '\0') { |
71 | if (!strcmp(options, "append")) | |
1da177e4 LT |
72 | append = 1; |
73 | else printf("hostfs_args - unsupported option - %s\n", | |
74 | options); | |
75 | } | |
76 | options = ptr; | |
77 | } | |
f1adc05e | 78 | return 0; |
1da177e4 LT |
79 | } |
80 | ||
81 | __uml_setup("hostfs=", hostfs_args, | |
82 | "hostfs=<root dir>,<flags>,...\n" | |
83 | " This is used to set hostfs parameters. The root directory argument\n" | |
84 | " is used to confine all hostfs mounts to within the specified directory\n" | |
85 | " tree on the host. If this isn't specified, then a user inside UML can\n" | |
86 | " mount anything on the host that's accessible to the user that's running\n" | |
87 | " it.\n" | |
88 | " The only flag currently supported is 'append', which specifies that all\n" | |
89 | " files opened by hostfs will be opened in append mode.\n\n" | |
90 | ); | |
91 | #endif | |
92 | ||
e9193059 | 93 | static char *__dentry_name(struct dentry *dentry, char *name) |
1da177e4 | 94 | { |
e9193059 AV |
95 | char *p = __dentry_path(dentry, name, PATH_MAX); |
96 | char *root; | |
97 | size_t len; | |
1da177e4 | 98 | |
e9193059 | 99 | spin_unlock(&dcache_lock); |
1da177e4 | 100 | |
e9193059 AV |
101 | root = dentry->d_sb->s_fs_info; |
102 | len = strlen(root); | |
103 | if (IS_ERR(p)) { | |
104 | __putname(name); | |
f1adc05e | 105 | return NULL; |
1da177e4 | 106 | } |
e9193059 AV |
107 | strncpy(name, root, PATH_MAX); |
108 | if (len > p - name) { | |
109 | __putname(name); | |
110 | return NULL; | |
111 | } | |
112 | if (p > name + len) { | |
113 | char *s = name + len; | |
114 | while ((*s++ = *p++) != '\0') | |
115 | ; | |
116 | } | |
f1adc05e | 117 | return name; |
1da177e4 LT |
118 | } |
119 | ||
e9193059 AV |
120 | static char *dentry_name(struct dentry *dentry) |
121 | { | |
122 | char *name = __getname(); | |
123 | if (!name) | |
124 | return NULL; | |
125 | ||
126 | spin_lock(&dcache_lock); | |
127 | return __dentry_name(dentry, name); /* will unlock */ | |
128 | } | |
129 | ||
c5322220 | 130 | static char *inode_name(struct inode *ino) |
1da177e4 LT |
131 | { |
132 | struct dentry *dentry; | |
e9193059 AV |
133 | char *name = __getname(); |
134 | if (!name) | |
135 | return NULL; | |
1da177e4 | 136 | |
e9193059 AV |
137 | spin_lock(&dcache_lock); |
138 | if (list_empty(&ino->i_dentry)) { | |
139 | spin_unlock(&dcache_lock); | |
140 | __putname(name); | |
141 | return NULL; | |
142 | } | |
143 | dentry = list_first_entry(&ino->i_dentry, struct dentry, d_alias); | |
144 | return __dentry_name(dentry, name); /* will unlock */ | |
1da177e4 LT |
145 | } |
146 | ||
1da177e4 LT |
147 | static char *follow_link(char *link) |
148 | { | |
149 | int len, n; | |
150 | char *name, *resolved, *end; | |
151 | ||
152 | len = 64; | |
84b3db04 | 153 | while (1) { |
1da177e4 LT |
154 | n = -ENOMEM; |
155 | name = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 156 | if (name == NULL) |
1da177e4 LT |
157 | goto out; |
158 | ||
ea7e743e | 159 | n = hostfs_do_readlink(link, name, len); |
84b3db04 | 160 | if (n < len) |
1da177e4 LT |
161 | break; |
162 | len *= 2; | |
163 | kfree(name); | |
164 | } | |
84b3db04 | 165 | if (n < 0) |
1da177e4 LT |
166 | goto out_free; |
167 | ||
84b3db04 | 168 | if (*name == '/') |
f1adc05e | 169 | return name; |
1da177e4 LT |
170 | |
171 | end = strrchr(link, '/'); | |
84b3db04 | 172 | if (end == NULL) |
f1adc05e | 173 | return name; |
1da177e4 LT |
174 | |
175 | *(end + 1) = '\0'; | |
176 | len = strlen(link) + strlen(name) + 1; | |
177 | ||
178 | resolved = kmalloc(len, GFP_KERNEL); | |
84b3db04 | 179 | if (resolved == NULL) { |
1da177e4 LT |
180 | n = -ENOMEM; |
181 | goto out_free; | |
182 | } | |
183 | ||
184 | sprintf(resolved, "%s%s", link, name); | |
185 | kfree(name); | |
186 | kfree(link); | |
f1adc05e | 187 | return resolved; |
1da177e4 LT |
188 | |
189 | out_free: | |
190 | kfree(name); | |
191 | out: | |
f1adc05e | 192 | return ERR_PTR(n); |
1da177e4 LT |
193 | } |
194 | ||
0a370e5d DH |
195 | static struct inode *hostfs_iget(struct super_block *sb) |
196 | { | |
52b209f7 | 197 | struct inode *inode = new_inode(sb); |
0a370e5d DH |
198 | if (!inode) |
199 | return ERR_PTR(-ENOMEM); | |
0a370e5d DH |
200 | return inode; |
201 | } | |
202 | ||
726c3342 | 203 | int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf) |
1da177e4 | 204 | { |
84b3db04 JD |
205 | /* |
206 | * do_statfs uses struct statfs64 internally, but the linux kernel | |
1da177e4 LT |
207 | * struct statfs still has 32-bit versions for most of these fields, |
208 | * so we convert them here | |
209 | */ | |
210 | int err; | |
211 | long long f_blocks; | |
212 | long long f_bfree; | |
213 | long long f_bavail; | |
214 | long long f_files; | |
215 | long long f_ffree; | |
216 | ||
601d2c38 | 217 | err = do_statfs(dentry->d_sb->s_fs_info, |
1da177e4 LT |
218 | &sf->f_bsize, &f_blocks, &f_bfree, &f_bavail, &f_files, |
219 | &f_ffree, &sf->f_fsid, sizeof(sf->f_fsid), | |
220 | &sf->f_namelen, sf->f_spare); | |
84b3db04 | 221 | if (err) |
f1adc05e | 222 | return err; |
1da177e4 LT |
223 | sf->f_blocks = f_blocks; |
224 | sf->f_bfree = f_bfree; | |
225 | sf->f_bavail = f_bavail; | |
226 | sf->f_files = f_files; | |
227 | sf->f_ffree = f_ffree; | |
228 | sf->f_type = HOSTFS_SUPER_MAGIC; | |
f1adc05e | 229 | return 0; |
1da177e4 LT |
230 | } |
231 | ||
232 | static struct inode *hostfs_alloc_inode(struct super_block *sb) | |
233 | { | |
234 | struct hostfs_inode_info *hi; | |
235 | ||
601d2c38 | 236 | hi = kzalloc(sizeof(*hi), GFP_KERNEL); |
84b3db04 | 237 | if (hi == NULL) |
f1adc05e | 238 | return NULL; |
601d2c38 | 239 | hi->fd = -1; |
1da177e4 | 240 | inode_init_once(&hi->vfs_inode); |
f1adc05e | 241 | return &hi->vfs_inode; |
1da177e4 LT |
242 | } |
243 | ||
e971a6d7 | 244 | static void hostfs_evict_inode(struct inode *inode) |
1da177e4 | 245 | { |
fef26658 | 246 | truncate_inode_pages(&inode->i_data, 0); |
e971a6d7 | 247 | end_writeback(inode); |
84b3db04 | 248 | if (HOSTFS_I(inode)->fd != -1) { |
1da177e4 LT |
249 | close_file(&HOSTFS_I(inode)->fd); |
250 | HOSTFS_I(inode)->fd = -1; | |
251 | } | |
1da177e4 LT |
252 | } |
253 | ||
254 | static void hostfs_destroy_inode(struct inode *inode) | |
255 | { | |
1da177e4 LT |
256 | kfree(HOSTFS_I(inode)); |
257 | } | |
258 | ||
dd2cc4df MS |
259 | static int hostfs_show_options(struct seq_file *seq, struct vfsmount *vfs) |
260 | { | |
601d2c38 | 261 | const char *root_path = vfs->mnt_sb->s_fs_info; |
dd2cc4df MS |
262 | size_t offset = strlen(root_ino) + 1; |
263 | ||
264 | if (strlen(root_path) > offset) | |
265 | seq_printf(seq, ",%s", root_path + offset); | |
266 | ||
267 | return 0; | |
268 | } | |
269 | ||
ee9b6d61 | 270 | static const struct super_operations hostfs_sbops = { |
1da177e4 | 271 | .alloc_inode = hostfs_alloc_inode, |
1da177e4 | 272 | .destroy_inode = hostfs_destroy_inode, |
e971a6d7 | 273 | .evict_inode = hostfs_evict_inode, |
1da177e4 | 274 | .statfs = hostfs_statfs, |
dd2cc4df | 275 | .show_options = hostfs_show_options, |
1da177e4 LT |
276 | }; |
277 | ||
278 | int hostfs_readdir(struct file *file, void *ent, filldir_t filldir) | |
279 | { | |
280 | void *dir; | |
281 | char *name; | |
282 | unsigned long long next, ino; | |
283 | int error, len; | |
284 | ||
c5322220 | 285 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 286 | if (name == NULL) |
f1adc05e | 287 | return -ENOMEM; |
1da177e4 | 288 | dir = open_dir(name, &error); |
e9193059 | 289 | __putname(name); |
84b3db04 | 290 | if (dir == NULL) |
f1adc05e | 291 | return -error; |
1da177e4 | 292 | next = file->f_pos; |
84b3db04 | 293 | while ((name = read_dir(dir, &next, &ino, &len)) != NULL) { |
1da177e4 LT |
294 | error = (*filldir)(ent, name, len, file->f_pos, |
295 | ino, DT_UNKNOWN); | |
84b3db04 | 296 | if (error) break; |
1da177e4 LT |
297 | file->f_pos = next; |
298 | } | |
299 | close_dir(dir); | |
f1adc05e | 300 | return 0; |
1da177e4 LT |
301 | } |
302 | ||
303 | int hostfs_file_open(struct inode *ino, struct file *file) | |
304 | { | |
305 | char *name; | |
aeb5d727 AV |
306 | fmode_t mode = 0; |
307 | int r = 0, w = 0, fd; | |
1da177e4 LT |
308 | |
309 | mode = file->f_mode & (FMODE_READ | FMODE_WRITE); | |
84b3db04 | 310 | if ((mode & HOSTFS_I(ino)->mode) == mode) |
f1adc05e | 311 | return 0; |
1da177e4 | 312 | |
84b3db04 JD |
313 | /* |
314 | * The file may already have been opened, but with the wrong access, | |
1da177e4 LT |
315 | * so this resets things and reopens the file with the new access. |
316 | */ | |
84b3db04 | 317 | if (HOSTFS_I(ino)->fd != -1) { |
1da177e4 LT |
318 | close_file(&HOSTFS_I(ino)->fd); |
319 | HOSTFS_I(ino)->fd = -1; | |
320 | } | |
321 | ||
322 | HOSTFS_I(ino)->mode |= mode; | |
84b3db04 | 323 | if (HOSTFS_I(ino)->mode & FMODE_READ) |
1da177e4 | 324 | r = 1; |
84b3db04 | 325 | if (HOSTFS_I(ino)->mode & FMODE_WRITE) |
1da177e4 | 326 | w = 1; |
84b3db04 | 327 | if (w) |
1da177e4 LT |
328 | r = 1; |
329 | ||
c5322220 | 330 | name = dentry_name(file->f_path.dentry); |
84b3db04 | 331 | if (name == NULL) |
f1adc05e | 332 | return -ENOMEM; |
1da177e4 LT |
333 | |
334 | fd = open_file(name, r, w, append); | |
e9193059 | 335 | __putname(name); |
84b3db04 | 336 | if (fd < 0) |
f1adc05e | 337 | return fd; |
1da177e4 LT |
338 | FILE_HOSTFS_I(file)->fd = fd; |
339 | ||
f1adc05e | 340 | return 0; |
1da177e4 LT |
341 | } |
342 | ||
7ea80859 | 343 | int hostfs_fsync(struct file *file, int datasync) |
1da177e4 | 344 | { |
7ea80859 | 345 | return fsync_file(HOSTFS_I(file->f_mapping->host)->fd, datasync); |
1da177e4 LT |
346 | } |
347 | ||
4b6f5d20 | 348 | static const struct file_operations hostfs_file_fops = { |
1da177e4 | 349 | .llseek = generic_file_llseek, |
543ade1f | 350 | .read = do_sync_read, |
5ffc4ef4 | 351 | .splice_read = generic_file_splice_read, |
1da177e4 LT |
352 | .aio_read = generic_file_aio_read, |
353 | .aio_write = generic_file_aio_write, | |
543ade1f | 354 | .write = do_sync_write, |
1da177e4 LT |
355 | .mmap = generic_file_mmap, |
356 | .open = hostfs_file_open, | |
357 | .release = NULL, | |
358 | .fsync = hostfs_fsync, | |
359 | }; | |
360 | ||
4b6f5d20 | 361 | static const struct file_operations hostfs_dir_fops = { |
1da177e4 LT |
362 | .llseek = generic_file_llseek, |
363 | .readdir = hostfs_readdir, | |
364 | .read = generic_read_dir, | |
365 | }; | |
366 | ||
367 | int hostfs_writepage(struct page *page, struct writeback_control *wbc) | |
368 | { | |
369 | struct address_space *mapping = page->mapping; | |
370 | struct inode *inode = mapping->host; | |
371 | char *buffer; | |
372 | unsigned long long base; | |
373 | int count = PAGE_CACHE_SIZE; | |
374 | int end_index = inode->i_size >> PAGE_CACHE_SHIFT; | |
375 | int err; | |
376 | ||
377 | if (page->index >= end_index) | |
378 | count = inode->i_size & (PAGE_CACHE_SIZE-1); | |
379 | ||
380 | buffer = kmap(page); | |
381 | base = ((unsigned long long) page->index) << PAGE_CACHE_SHIFT; | |
382 | ||
383 | err = write_file(HOSTFS_I(inode)->fd, &base, buffer, count); | |
84b3db04 | 384 | if (err != count) { |
1da177e4 LT |
385 | ClearPageUptodate(page); |
386 | goto out; | |
387 | } | |
388 | ||
389 | if (base > inode->i_size) | |
390 | inode->i_size = base; | |
391 | ||
392 | if (PageError(page)) | |
393 | ClearPageError(page); | |
394 | err = 0; | |
395 | ||
396 | out: | |
397 | kunmap(page); | |
398 | ||
399 | unlock_page(page); | |
400 | return err; | |
401 | } | |
402 | ||
403 | int hostfs_readpage(struct file *file, struct page *page) | |
404 | { | |
405 | char *buffer; | |
406 | long long start; | |
407 | int err = 0; | |
408 | ||
409 | start = (long long) page->index << PAGE_CACHE_SHIFT; | |
410 | buffer = kmap(page); | |
411 | err = read_file(FILE_HOSTFS_I(file)->fd, &start, buffer, | |
412 | PAGE_CACHE_SIZE); | |
84b3db04 JD |
413 | if (err < 0) |
414 | goto out; | |
1da177e4 LT |
415 | |
416 | memset(&buffer[err], 0, PAGE_CACHE_SIZE - err); | |
417 | ||
418 | flush_dcache_page(page); | |
419 | SetPageUptodate(page); | |
420 | if (PageError(page)) ClearPageError(page); | |
421 | err = 0; | |
422 | out: | |
423 | kunmap(page); | |
424 | unlock_page(page); | |
f1adc05e | 425 | return err; |
1da177e4 LT |
426 | } |
427 | ||
ae361ff4 NP |
428 | int hostfs_write_begin(struct file *file, struct address_space *mapping, |
429 | loff_t pos, unsigned len, unsigned flags, | |
430 | struct page **pagep, void **fsdata) | |
1da177e4 | 431 | { |
ae361ff4 | 432 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
1da177e4 | 433 | |
54566b2c | 434 | *pagep = grab_cache_page_write_begin(mapping, index, flags); |
ae361ff4 NP |
435 | if (!*pagep) |
436 | return -ENOMEM; | |
437 | return 0; | |
1da177e4 LT |
438 | } |
439 | ||
ae361ff4 NP |
440 | int hostfs_write_end(struct file *file, struct address_space *mapping, |
441 | loff_t pos, unsigned len, unsigned copied, | |
442 | struct page *page, void *fsdata) | |
1da177e4 | 443 | { |
1da177e4 | 444 | struct inode *inode = mapping->host; |
ae361ff4 NP |
445 | void *buffer; |
446 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
447 | int err; | |
1da177e4 | 448 | |
1da177e4 | 449 | buffer = kmap(page); |
ae361ff4 NP |
450 | err = write_file(FILE_HOSTFS_I(file)->fd, &pos, buffer + from, copied); |
451 | kunmap(page); | |
30f04a4e | 452 | |
ae361ff4 NP |
453 | if (!PageUptodate(page) && err == PAGE_CACHE_SIZE) |
454 | SetPageUptodate(page); | |
30f04a4e | 455 | |
84b3db04 JD |
456 | /* |
457 | * If err > 0, write_file has added err to pos, so we are comparing | |
ae361ff4 NP |
458 | * i_size against the last byte written. |
459 | */ | |
460 | if (err > 0 && (pos > inode->i_size)) | |
461 | inode->i_size = pos; | |
462 | unlock_page(page); | |
463 | page_cache_release(page); | |
1da177e4 | 464 | |
f1adc05e | 465 | return err; |
1da177e4 LT |
466 | } |
467 | ||
f5e54d6e | 468 | static const struct address_space_operations hostfs_aops = { |
1da177e4 LT |
469 | .writepage = hostfs_writepage, |
470 | .readpage = hostfs_readpage, | |
ffa0aea6 | 471 | .set_page_dirty = __set_page_dirty_nobuffers, |
ae361ff4 NP |
472 | .write_begin = hostfs_write_begin, |
473 | .write_end = hostfs_write_end, | |
1da177e4 LT |
474 | }; |
475 | ||
4754b825 | 476 | static int read_name(struct inode *ino, char *name) |
1da177e4 | 477 | { |
4754b825 AV |
478 | dev_t rdev; |
479 | struct hostfs_stat st; | |
480 | int err = stat_file(name, &st, -1); | |
481 | if (err) | |
482 | return err; | |
1da177e4 | 483 | |
5e2df28c | 484 | /* Reencode maj and min with the kernel encoding.*/ |
4754b825 | 485 | rdev = MKDEV(st.maj, st.min); |
1da177e4 | 486 | |
4754b825 AV |
487 | switch (st.mode & S_IFMT) { |
488 | case S_IFLNK: | |
d0352d3e | 489 | ino->i_op = &hostfs_link_iops; |
1da177e4 | 490 | break; |
4754b825 AV |
491 | case S_IFDIR: |
492 | ino->i_op = &hostfs_dir_iops; | |
493 | ino->i_fop = &hostfs_dir_fops; | |
1da177e4 | 494 | break; |
4754b825 AV |
495 | case S_IFCHR: |
496 | case S_IFBLK: | |
497 | case S_IFIFO: | |
498 | case S_IFSOCK: | |
499 | init_special_inode(ino, st.mode & S_IFMT, rdev); | |
500 | ino->i_op = &hostfs_iops; | |
1da177e4 | 501 | break; |
4754b825 AV |
502 | |
503 | default: | |
504 | ino->i_op = &hostfs_iops; | |
505 | ino->i_fop = &hostfs_file_fops; | |
506 | ino->i_mapping->a_ops = &hostfs_aops; | |
1da177e4 | 507 | } |
4754b825 AV |
508 | |
509 | ino->i_ino = st.ino; | |
510 | ino->i_mode = st.mode; | |
511 | ino->i_nlink = st.nlink; | |
512 | ino->i_uid = st.uid; | |
513 | ino->i_gid = st.gid; | |
514 | ino->i_atime = st.atime; | |
515 | ino->i_mtime = st.mtime; | |
516 | ino->i_ctime = st.ctime; | |
517 | ino->i_size = st.size; | |
518 | ino->i_blocks = st.blocks; | |
519 | return 0; | |
1da177e4 LT |
520 | } |
521 | ||
522 | int hostfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
84b3db04 | 523 | struct nameidata *nd) |
1da177e4 LT |
524 | { |
525 | struct inode *inode; | |
526 | char *name; | |
527 | int error, fd; | |
528 | ||
0a370e5d DH |
529 | inode = hostfs_iget(dir->i_sb); |
530 | if (IS_ERR(inode)) { | |
531 | error = PTR_ERR(inode); | |
84b3db04 | 532 | goto out; |
0a370e5d | 533 | } |
1da177e4 | 534 | |
1da177e4 | 535 | error = -ENOMEM; |
c5322220 | 536 | name = dentry_name(dentry); |
84b3db04 | 537 | if (name == NULL) |
1da177e4 LT |
538 | goto out_put; |
539 | ||
540 | fd = file_create(name, | |
541 | mode & S_IRUSR, mode & S_IWUSR, mode & S_IXUSR, | |
542 | mode & S_IRGRP, mode & S_IWGRP, mode & S_IXGRP, | |
543 | mode & S_IROTH, mode & S_IWOTH, mode & S_IXOTH); | |
4754b825 | 544 | if (fd < 0) |
1da177e4 | 545 | error = fd; |
4754b825 | 546 | else |
5e2df28c | 547 | error = read_name(inode, name); |
1da177e4 | 548 | |
e9193059 | 549 | __putname(name); |
84b3db04 | 550 | if (error) |
1da177e4 LT |
551 | goto out_put; |
552 | ||
553 | HOSTFS_I(inode)->fd = fd; | |
554 | HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE; | |
555 | d_instantiate(dentry, inode); | |
f1adc05e | 556 | return 0; |
1da177e4 LT |
557 | |
558 | out_put: | |
559 | iput(inode); | |
560 | out: | |
f1adc05e | 561 | return error; |
1da177e4 LT |
562 | } |
563 | ||
564 | struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry, | |
f1adc05e | 565 | struct nameidata *nd) |
1da177e4 LT |
566 | { |
567 | struct inode *inode; | |
568 | char *name; | |
569 | int err; | |
570 | ||
0a370e5d DH |
571 | inode = hostfs_iget(ino->i_sb); |
572 | if (IS_ERR(inode)) { | |
573 | err = PTR_ERR(inode); | |
1da177e4 | 574 | goto out; |
0a370e5d | 575 | } |
1da177e4 | 576 | |
1da177e4 | 577 | err = -ENOMEM; |
c5322220 | 578 | name = dentry_name(dentry); |
84b3db04 | 579 | if (name == NULL) |
1da177e4 LT |
580 | goto out_put; |
581 | ||
582 | err = read_name(inode, name); | |
5e2df28c | 583 | |
e9193059 | 584 | __putname(name); |
84b3db04 | 585 | if (err == -ENOENT) { |
1da177e4 LT |
586 | iput(inode); |
587 | inode = NULL; | |
588 | } | |
84b3db04 | 589 | else if (err) |
1da177e4 LT |
590 | goto out_put; |
591 | ||
592 | d_add(dentry, inode); | |
593 | dentry->d_op = &hostfs_dentry_ops; | |
f1adc05e | 594 | return NULL; |
1da177e4 LT |
595 | |
596 | out_put: | |
597 | iput(inode); | |
598 | out: | |
f1adc05e | 599 | return ERR_PTR(err); |
1da177e4 LT |
600 | } |
601 | ||
1da177e4 LT |
602 | int hostfs_link(struct dentry *to, struct inode *ino, struct dentry *from) |
603 | { | |
f1adc05e JD |
604 | char *from_name, *to_name; |
605 | int err; | |
1da177e4 | 606 | |
c5322220 | 607 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 608 | return -ENOMEM; |
c5322220 | 609 | to_name = dentry_name(to); |
84b3db04 | 610 | if (to_name == NULL) { |
e9193059 | 611 | __putname(from_name); |
f1adc05e | 612 | return -ENOMEM; |
1da177e4 | 613 | } |
f1adc05e | 614 | err = link_file(to_name, from_name); |
e9193059 AV |
615 | __putname(from_name); |
616 | __putname(to_name); | |
f1adc05e | 617 | return err; |
1da177e4 LT |
618 | } |
619 | ||
620 | int hostfs_unlink(struct inode *ino, struct dentry *dentry) | |
621 | { | |
622 | char *file; | |
623 | int err; | |
624 | ||
c5322220 | 625 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 626 | return -ENOMEM; |
84b3db04 | 627 | if (append) |
f1adc05e | 628 | return -EPERM; |
1da177e4 LT |
629 | |
630 | err = unlink_file(file); | |
e9193059 | 631 | __putname(file); |
f1adc05e | 632 | return err; |
1da177e4 LT |
633 | } |
634 | ||
635 | int hostfs_symlink(struct inode *ino, struct dentry *dentry, const char *to) | |
636 | { | |
637 | char *file; | |
638 | int err; | |
639 | ||
c5322220 | 640 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 641 | return -ENOMEM; |
1da177e4 | 642 | err = make_symlink(file, to); |
e9193059 | 643 | __putname(file); |
f1adc05e | 644 | return err; |
1da177e4 LT |
645 | } |
646 | ||
647 | int hostfs_mkdir(struct inode *ino, struct dentry *dentry, int mode) | |
648 | { | |
649 | char *file; | |
650 | int err; | |
651 | ||
c5322220 | 652 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 653 | return -ENOMEM; |
1da177e4 | 654 | err = do_mkdir(file, mode); |
e9193059 | 655 | __putname(file); |
f1adc05e | 656 | return err; |
1da177e4 LT |
657 | } |
658 | ||
659 | int hostfs_rmdir(struct inode *ino, struct dentry *dentry) | |
660 | { | |
661 | char *file; | |
662 | int err; | |
663 | ||
c5322220 | 664 | if ((file = dentry_name(dentry)) == NULL) |
f1adc05e | 665 | return -ENOMEM; |
1da177e4 | 666 | err = do_rmdir(file); |
e9193059 | 667 | __putname(file); |
f1adc05e | 668 | return err; |
1da177e4 LT |
669 | } |
670 | ||
671 | int hostfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) | |
672 | { | |
673 | struct inode *inode; | |
674 | char *name; | |
0a370e5d | 675 | int err; |
1da177e4 | 676 | |
0a370e5d DH |
677 | inode = hostfs_iget(dir->i_sb); |
678 | if (IS_ERR(inode)) { | |
679 | err = PTR_ERR(inode); | |
1da177e4 | 680 | goto out; |
0a370e5d | 681 | } |
1da177e4 | 682 | |
1da177e4 | 683 | err = -ENOMEM; |
c5322220 | 684 | name = dentry_name(dentry); |
84b3db04 | 685 | if (name == NULL) |
1da177e4 LT |
686 | goto out_put; |
687 | ||
688 | init_special_inode(inode, mode, dev); | |
88f6cd0c | 689 | err = do_mknod(name, mode, MAJOR(dev), MINOR(dev)); |
e9193059 | 690 | if (!err) |
1da177e4 LT |
691 | goto out_free; |
692 | ||
693 | err = read_name(inode, name); | |
e9193059 | 694 | __putname(name); |
5e2df28c AV |
695 | if (err) |
696 | goto out_put; | |
84b3db04 | 697 | if (err) |
1da177e4 LT |
698 | goto out_put; |
699 | ||
700 | d_instantiate(dentry, inode); | |
f1adc05e | 701 | return 0; |
1da177e4 LT |
702 | |
703 | out_free: | |
e9193059 | 704 | __putname(name); |
1da177e4 LT |
705 | out_put: |
706 | iput(inode); | |
707 | out: | |
f1adc05e | 708 | return err; |
1da177e4 LT |
709 | } |
710 | ||
711 | int hostfs_rename(struct inode *from_ino, struct dentry *from, | |
712 | struct inode *to_ino, struct dentry *to) | |
713 | { | |
714 | char *from_name, *to_name; | |
715 | int err; | |
716 | ||
c5322220 | 717 | if ((from_name = dentry_name(from)) == NULL) |
f1adc05e | 718 | return -ENOMEM; |
c5322220 | 719 | if ((to_name = dentry_name(to)) == NULL) { |
e9193059 | 720 | __putname(from_name); |
f1adc05e | 721 | return -ENOMEM; |
1da177e4 LT |
722 | } |
723 | err = rename_file(from_name, to_name); | |
e9193059 AV |
724 | __putname(from_name); |
725 | __putname(to_name); | |
f1adc05e | 726 | return err; |
1da177e4 LT |
727 | } |
728 | ||
e6305c43 | 729 | int hostfs_permission(struct inode *ino, int desired) |
1da177e4 LT |
730 | { |
731 | char *name; | |
732 | int r = 0, w = 0, x = 0, err; | |
733 | ||
734 | if (desired & MAY_READ) r = 1; | |
735 | if (desired & MAY_WRITE) w = 1; | |
736 | if (desired & MAY_EXEC) x = 1; | |
c5322220 | 737 | name = inode_name(ino); |
f1adc05e JD |
738 | if (name == NULL) |
739 | return -ENOMEM; | |
1da177e4 LT |
740 | |
741 | if (S_ISCHR(ino->i_mode) || S_ISBLK(ino->i_mode) || | |
84b3db04 | 742 | S_ISFIFO(ino->i_mode) || S_ISSOCK(ino->i_mode)) |
1da177e4 LT |
743 | err = 0; |
744 | else | |
745 | err = access_file(name, r, w, x); | |
e9193059 | 746 | __putname(name); |
84b3db04 | 747 | if (!err) |
1da177e4 LT |
748 | err = generic_permission(ino, desired, NULL); |
749 | return err; | |
750 | } | |
751 | ||
752 | int hostfs_setattr(struct dentry *dentry, struct iattr *attr) | |
753 | { | |
1025774c | 754 | struct inode *inode = dentry->d_inode; |
1da177e4 LT |
755 | struct hostfs_iattr attrs; |
756 | char *name; | |
757 | int err; | |
758 | ||
1025774c | 759 | int fd = HOSTFS_I(inode)->fd; |
5822b7fa | 760 | |
1025774c | 761 | err = inode_change_ok(inode, attr); |
1da177e4 LT |
762 | if (err) |
763 | return err; | |
764 | ||
84b3db04 | 765 | if (append) |
1da177e4 LT |
766 | attr->ia_valid &= ~ATTR_SIZE; |
767 | ||
768 | attrs.ia_valid = 0; | |
84b3db04 | 769 | if (attr->ia_valid & ATTR_MODE) { |
1da177e4 LT |
770 | attrs.ia_valid |= HOSTFS_ATTR_MODE; |
771 | attrs.ia_mode = attr->ia_mode; | |
772 | } | |
84b3db04 | 773 | if (attr->ia_valid & ATTR_UID) { |
1da177e4 LT |
774 | attrs.ia_valid |= HOSTFS_ATTR_UID; |
775 | attrs.ia_uid = attr->ia_uid; | |
776 | } | |
84b3db04 | 777 | if (attr->ia_valid & ATTR_GID) { |
1da177e4 LT |
778 | attrs.ia_valid |= HOSTFS_ATTR_GID; |
779 | attrs.ia_gid = attr->ia_gid; | |
780 | } | |
84b3db04 | 781 | if (attr->ia_valid & ATTR_SIZE) { |
1da177e4 LT |
782 | attrs.ia_valid |= HOSTFS_ATTR_SIZE; |
783 | attrs.ia_size = attr->ia_size; | |
784 | } | |
84b3db04 | 785 | if (attr->ia_valid & ATTR_ATIME) { |
1da177e4 LT |
786 | attrs.ia_valid |= HOSTFS_ATTR_ATIME; |
787 | attrs.ia_atime = attr->ia_atime; | |
788 | } | |
84b3db04 | 789 | if (attr->ia_valid & ATTR_MTIME) { |
1da177e4 LT |
790 | attrs.ia_valid |= HOSTFS_ATTR_MTIME; |
791 | attrs.ia_mtime = attr->ia_mtime; | |
792 | } | |
84b3db04 | 793 | if (attr->ia_valid & ATTR_CTIME) { |
1da177e4 LT |
794 | attrs.ia_valid |= HOSTFS_ATTR_CTIME; |
795 | attrs.ia_ctime = attr->ia_ctime; | |
796 | } | |
84b3db04 | 797 | if (attr->ia_valid & ATTR_ATIME_SET) { |
1da177e4 LT |
798 | attrs.ia_valid |= HOSTFS_ATTR_ATIME_SET; |
799 | } | |
84b3db04 | 800 | if (attr->ia_valid & ATTR_MTIME_SET) { |
1da177e4 LT |
801 | attrs.ia_valid |= HOSTFS_ATTR_MTIME_SET; |
802 | } | |
c5322220 | 803 | name = dentry_name(dentry); |
84b3db04 | 804 | if (name == NULL) |
f1adc05e | 805 | return -ENOMEM; |
5822b7fa | 806 | err = set_attr(name, &attrs, fd); |
e9193059 | 807 | __putname(name); |
84b3db04 | 808 | if (err) |
f1adc05e | 809 | return err; |
1da177e4 | 810 | |
1025774c CH |
811 | if ((attr->ia_valid & ATTR_SIZE) && |
812 | attr->ia_size != i_size_read(inode)) { | |
813 | int error; | |
814 | ||
815 | error = vmtruncate(inode, attr->ia_size); | |
816 | if (err) | |
817 | return err; | |
818 | } | |
819 | ||
820 | setattr_copy(inode, attr); | |
821 | mark_inode_dirty(inode); | |
822 | return 0; | |
1da177e4 LT |
823 | } |
824 | ||
92e1d5be | 825 | static const struct inode_operations hostfs_iops = { |
1da177e4 LT |
826 | .create = hostfs_create, |
827 | .link = hostfs_link, | |
828 | .unlink = hostfs_unlink, | |
829 | .symlink = hostfs_symlink, | |
830 | .mkdir = hostfs_mkdir, | |
831 | .rmdir = hostfs_rmdir, | |
832 | .mknod = hostfs_mknod, | |
833 | .rename = hostfs_rename, | |
1da177e4 LT |
834 | .permission = hostfs_permission, |
835 | .setattr = hostfs_setattr, | |
1da177e4 LT |
836 | }; |
837 | ||
92e1d5be | 838 | static const struct inode_operations hostfs_dir_iops = { |
1da177e4 LT |
839 | .create = hostfs_create, |
840 | .lookup = hostfs_lookup, | |
841 | .link = hostfs_link, | |
842 | .unlink = hostfs_unlink, | |
843 | .symlink = hostfs_symlink, | |
844 | .mkdir = hostfs_mkdir, | |
845 | .rmdir = hostfs_rmdir, | |
846 | .mknod = hostfs_mknod, | |
847 | .rename = hostfs_rename, | |
1da177e4 LT |
848 | .permission = hostfs_permission, |
849 | .setattr = hostfs_setattr, | |
1da177e4 LT |
850 | }; |
851 | ||
d0352d3e AV |
852 | static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
853 | { | |
854 | char *link = __getname(); | |
855 | if (link) { | |
856 | char *path = dentry_name(dentry); | |
857 | int err = -ENOMEM; | |
858 | if (path) { | |
859 | int err = hostfs_do_readlink(path, link, PATH_MAX); | |
860 | if (err == PATH_MAX) | |
861 | err = -E2BIG; | |
e9193059 | 862 | __putname(path); |
d0352d3e AV |
863 | } |
864 | if (err < 0) { | |
865 | __putname(link); | |
866 | link = ERR_PTR(err); | |
867 | } | |
868 | } else { | |
869 | link = ERR_PTR(-ENOMEM); | |
1da177e4 | 870 | } |
d0352d3e AV |
871 | |
872 | nd_set_link(nd, link); | |
873 | return NULL; | |
874 | } | |
875 | ||
876 | static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) | |
877 | { | |
878 | char *s = nd_get_link(nd); | |
879 | if (!IS_ERR(s)) | |
880 | __putname(s); | |
1da177e4 LT |
881 | } |
882 | ||
d0352d3e AV |
883 | static const struct inode_operations hostfs_link_iops = { |
884 | .readlink = generic_readlink, | |
885 | .follow_link = hostfs_follow_link, | |
886 | .put_link = hostfs_put_link, | |
1da177e4 LT |
887 | }; |
888 | ||
889 | static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent) | |
890 | { | |
891 | struct inode *root_inode; | |
75e8defb | 892 | char *host_root_path, *req_root = d; |
1da177e4 LT |
893 | int err; |
894 | ||
895 | sb->s_blocksize = 1024; | |
896 | sb->s_blocksize_bits = 10; | |
897 | sb->s_magic = HOSTFS_SUPER_MAGIC; | |
898 | sb->s_op = &hostfs_sbops; | |
752fa51e | 899 | sb->s_maxbytes = MAX_LFS_FILESIZE; |
1da177e4 | 900 | |
a6eb0be6 | 901 | /* NULL is printed as <NULL> by sprintf: avoid that. */ |
75e8defb PBG |
902 | if (req_root == NULL) |
903 | req_root = ""; | |
1da177e4 LT |
904 | |
905 | err = -ENOMEM; | |
601d2c38 AV |
906 | sb->s_fs_info = host_root_path = |
907 | kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL); | |
84b3db04 | 908 | if (host_root_path == NULL) |
1da177e4 LT |
909 | goto out; |
910 | ||
75e8defb | 911 | sprintf(host_root_path, "%s/%s", root_ino, req_root); |
1da177e4 | 912 | |
52b209f7 AV |
913 | root_inode = new_inode(sb); |
914 | if (!root_inode) | |
601d2c38 | 915 | goto out; |
1da177e4 | 916 | |
4754b825 AV |
917 | err = read_name(root_inode, host_root_path); |
918 | if (err) | |
919 | goto out_put; | |
52b209f7 | 920 | |
4754b825 | 921 | if (S_ISLNK(root_inode->i_mode)) { |
52b209f7 AV |
922 | char *name = follow_link(host_root_path); |
923 | if (IS_ERR(name)) | |
924 | err = PTR_ERR(name); | |
925 | else | |
926 | err = read_name(root_inode, name); | |
927 | kfree(name); | |
4754b825 AV |
928 | if (err) |
929 | goto out_put; | |
52b209f7 | 930 | } |
1da177e4 | 931 | |
1da177e4 LT |
932 | err = -ENOMEM; |
933 | sb->s_root = d_alloc_root(root_inode); | |
84b3db04 | 934 | if (sb->s_root == NULL) |
1da177e4 LT |
935 | goto out_put; |
936 | ||
f1adc05e | 937 | return 0; |
1da177e4 | 938 | |
f1adc05e JD |
939 | out_put: |
940 | iput(root_inode); | |
f1adc05e JD |
941 | out: |
942 | return err; | |
1da177e4 LT |
943 | } |
944 | ||
454e2398 DH |
945 | static int hostfs_read_sb(struct file_system_type *type, |
946 | int flags, const char *dev_name, | |
947 | void *data, struct vfsmount *mnt) | |
1da177e4 | 948 | { |
454e2398 | 949 | return get_sb_nodev(type, flags, data, hostfs_fill_sb_common, mnt); |
1da177e4 LT |
950 | } |
951 | ||
601d2c38 AV |
952 | static void hostfs_kill_sb(struct super_block *s) |
953 | { | |
954 | kill_anon_super(s); | |
955 | kfree(s->s_fs_info); | |
956 | } | |
957 | ||
1da177e4 LT |
958 | static struct file_system_type hostfs_type = { |
959 | .owner = THIS_MODULE, | |
960 | .name = "hostfs", | |
961 | .get_sb = hostfs_read_sb, | |
601d2c38 | 962 | .kill_sb = hostfs_kill_sb, |
1da177e4 LT |
963 | .fs_flags = 0, |
964 | }; | |
965 | ||
966 | static int __init init_hostfs(void) | |
967 | { | |
f1adc05e | 968 | return register_filesystem(&hostfs_type); |
1da177e4 LT |
969 | } |
970 | ||
971 | static void __exit exit_hostfs(void) | |
972 | { | |
973 | unregister_filesystem(&hostfs_type); | |
974 | } | |
975 | ||
976 | module_init(init_hostfs) | |
977 | module_exit(exit_hostfs) | |
978 | MODULE_LICENSE("GPL"); |